diff --git a/lib/Paymill/Models/Request/Preauthorization.php b/lib/Paymill/Models/Request/Preauthorization.php
index 437186d..aa7fc46 100644
--- a/lib/Paymill/Models/Request/Preauthorization.php
+++ b/lib/Paymill/Models/Request/Preauthorization.php
@@ -30,6 +30,13 @@ class Preauthorization extends Base
      */
     private $_token;
 
+    /**
+     * Source
+     *
+     * @var $_source
+     */
+    private $_source;
+
     /**
      * @var string
      */
@@ -128,6 +135,30 @@ public function setToken($token)
         return $this;
     }
 
+    /**
+     * Sets the name of origin of the call creating the transaction.
+     *
+     * @param string $source Source
+     *
+     * @return $this
+     */
+    public function setSource($source)
+    {
+        $this->_source = $source;
+
+        return $this;
+    }
+
+    /**
+     * Gets the name of origin of the call creating the transaction.
+     *
+     * @return string
+     */
+    public function getSource()
+    {
+        return $this->_source;
+    }
+
     /**
      * Returns the description
      * @return string
@@ -189,7 +220,9 @@ public function parameterize($method)
                 if (!is_null($this->getClient())) {
                     $parameterArray['client'] = $this->getClient();
                 }
-
+                if(!is_null($this->getSource())) {
+                    $parameterArray['source'] = $this->getSource();
+                }
                 break;
             case 'getOne':
                 $parameterArray['count'] = 1;
diff --git a/lib/Paymill/Request.php b/lib/Paymill/Request.php
index c49d697..b7f4b99 100644
--- a/lib/Paymill/Request.php
+++ b/lib/Paymill/Request.php
@@ -222,8 +222,11 @@ private function _request(Base $model, $method)
         $parameter = $model->parameterize($method);
         $serviceResource = $model->getServiceResource() . $model->getId();
 
-        if(is_a($model, '\Paymill\Models\Request\Transaction') && $method === "create") {
-            $source = !array_key_exists('source',$parameter) ?
+        if ((is_a($model, '\Paymill\Models\Request\Transaction')
+                || is_a($model, '\Paymill\Models\Request\Preauthorization'))
+            && $method === "create"
+        ) {
+            $source = !array_key_exists('source', $parameter) ?
                 "PhpLib" . $this->getVersion() :
                 "PhpLib" . $this->getVersion() . "_" . $parameter['source'];
             $parameter['source'] = $source;
diff --git a/tests/unit/Paymill/Models/Request/PreauthorizationTest.php b/tests/unit/Paymill/Models/Request/PreauthorizationTest.php
index 8104a94..9065d68 100644
--- a/tests/unit/Paymill/Models/Request/PreauthorizationTest.php
+++ b/tests/unit/Paymill/Models/Request/PreauthorizationTest.php
@@ -42,12 +42,13 @@ protected function tearDown()
     public function setGetTest()
     {
         $sample = array(
-            'token' => '098f6bcd4621d373cade4e832627b4f6',
-            'payment' => 'pay_d43cf0ee969d9847512b',
-            'amount' => '4200',
-            'currency' => 'EUR',
+            'token'       => '098f6bcd4621d373cade4e832627b4f6',
+            'payment'     => 'pay_d43cf0ee969d9847512b',
+            'amount'      => '4200',
+            'currency'    => 'EUR',
             'description' => 'Test Description',
-            'client' => 'client_4624bcfbac1f4862642f'
+            'source'      => 'Test Source',
+            'client'      => 'client_4624bcfbac1f4862642f',
         );
 
         $this->_preauthorization
@@ -55,6 +56,7 @@ public function setGetTest()
             ->setToken($sample['token'])
             ->setAmount($sample['amount'])
             ->setCurrency($sample['currency'])
+            ->setSource(($sample['source']))
             ->setDescription($sample['description'])
             ->setClient($sample['client']);
 
@@ -64,6 +66,7 @@ public function setGetTest()
         $this->assertEquals($this->_preauthorization->getCurrency(), $sample['currency']);
         $this->assertEquals($this->_preauthorization->getDescription(), $sample['description']);
         $this->assertEquals($this->_preauthorization->getClient(), $sample['client']);
+        $this->assertEquals($this->_preauthorization->getSource(), $sample['source']);
 
         return $this->_preauthorization;
     }
@@ -86,7 +89,8 @@ public function parameterizeTest($preauthorization)
             'amount' => '4200',
             'currency' => 'EUR',
             'description' => 'Test Description',
-            'client' => 'client_4624bcfbac1f4862642f'
+            'client' => 'client_4624bcfbac1f4862642f',
+            'source' => 'Test Source'
             )
         );
         $this->assertEquals($getOneArray, array(